// Copyright 2006 Google Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//   http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// Known Issues:
//
// * Patterns only support repeat.
// * Radial gradient are not implemented. The VML version of these look very
//   different from the canvas one.
// * Clipping paths are not implemented.
// * Coordsize. The width and height attribute have higher priority than the
//   width and height style values which isn't correct.
// * Painting mode isn't implemented.
// * Canvas width/height should is using content-box by default. IE in
//   Quirks mode will draw the canvas using border-box. Either change your
//   doctype to HTML5
//   (http://www.whatwg.org/specs/web-apps/current-work/#the-doctype)
//   or use Box Sizing Behavior from WebFX
//   (http://webfx.eae.net/dhtml/boxsizing/boxsizing.html)
// * Non uniform scaling does not correctly scale strokes.
// * Optimize. There is always room for speed improvements.
// AMD by kener.linfeng@gmail.com


// Only add this code if we do not already have a canvas implementation
if (!document.createElement('canvas').getContext) {
    (function () {
        // alias some functions to make (compiled) code shorter
        var m = Math;
        var mr = m.round;
        var ms = m.sin;
        var mc = m.cos;
        var abs = m.abs;
        var sqrt = m.sqrt;
        // this is used for sub pixel precision
        var Z = 10;
        var Z2 = Z / 2;
        var IE_VERSION = +navigator.userAgent.match(/MSIE ([\d.]+)?/)[1];
        /**
   * This funtion is assigned to the <canvas> elements as element.getContext().
   * @this {HTMLElement}
   * @return {CanvasRenderingContext2D_}
   */
        function getContext() {
            return this.context_ || (this.context_ = new CanvasRenderingContext2D_(this));
        }
        var slice = Array.prototype.slice;
        /**
   * Binds a function to an object. The returned function will always use the
   * passed in {@code obj} as {@code this}.
   *
   * Example:
   *
   *   g = bind(f, obj, a, b)
   *   g(c, d) // will do f.call(obj, a, b, c, d)
   *
   * @param {Function} f The function to bind the object to
   * @param {Object} obj The object that should act as this when the function
   *     is called
   * @param {*} var_args Rest arguments that will be used as the initial
   *     arguments when the function is called
   * @return {Function} A new function that has bound this
   */
        function bind(f, obj, var_args) {
            var a = slice.call(arguments, 2);
            return function () {
                return f.apply(obj, a.concat(slice.call(arguments)));
            };
        }
        function encodeHtmlAttribute(s) {
            return String(s).replace(/&/g, '&amp;').replace(/"/g, '&quot;');
        }
        function addNamespace(doc, prefix, urn) {
            if (!doc.namespaces[prefix]) {
                doc.namespaces.add(prefix, urn, '#default#VML');
            }
        }
        function addNamespacesAndStylesheet(doc) {
            addNamespace(doc, 'g_vml_', 'urn:schemas-microsoft-com:vml');
            addNamespace(doc, 'g_o_', 'urn:schemas-microsoft-com:office:office');
            // Setup default CSS.  Only add one style sheet per document
            if (!doc.styleSheets['ex_canvas_']) {
                var ss = doc.createStyleSheet();
                ss.owningElement.id = 'ex_canvas_';
                ss.cssText = 'canvas{display:inline-block;overflow:hidden;' + // default size is 300x150 in Gecko and Opera
                'text-align:left;width:300px;height:150px}';
            }
        }
        // Add namespaces and stylesheet at startup.
        addNamespacesAndStylesheet(document);
        var G_vmlCanvasManager_ = {
            init: function (opt_doc) {
                var doc = opt_doc || document;
                // Create a dummy element so that IE will allow canvas elements to be
                // recognized.
                doc.createElement('canvas');
                doc.attachEvent('onreadystatechange', bind(this.init_, this, doc));
            },
            init_: function (doc) {
                // find all canvas elements
                var els = doc.getElementsByTagName('canvas');
                for (var i = 0; i < els.length; i++) {
                    this.initElement(els[i]);
                }
            },
            /**
     * Public initializes a canvas element so that it can be used as canvas
     * element from now on. This is called automatically before the page is
     * loaded but if you are creating elements using createElement you need to
     * make sure this is called on the element.
     * @param {HTMLElement} el The canvas element to initialize.
     * @return {HTMLElement} the element that was created.
     */
            initElement: function (el) {
                if (!el.getContext) {
                    el.getContext = getContext;
                    // Add namespaces and stylesheet to document of the element.
                    addNamespacesAndStylesheet(el.ownerDocument);
                    // Remove fallback content. There is no way to hide text nodes so we
                    // just remove all childNodes. We could hide all elements and remove
                    // text nodes but who really cares about the fallback content.
                    el.innerHTML = '';
                    // do not use inline function because that will leak memory
                    el.attachEvent('onpropertychange', onPropertyChange);
                    el.attachEvent('onresize', onResize);
                    var attrs = el.attributes;
                    if (attrs.width && attrs.width.specified) {
                        // TODO: use runtimeStyle and coordsize
                        // el.getContext().setWidth_(attrs.width.nodeValue);
                        el.style.width = attrs.width.nodeValue + 'px';
                    } else {
                        el.width = el.clientWidth;
                    }
                    if (attrs.height && attrs.height.specified) {
                        // TODO: use runtimeStyle and coordsize
                        // el.getContext().setHeight_(attrs.height.nodeValue);
                        el.style.height = attrs.height.nodeValue + 'px';
                    } else {
                        el.height = el.clientHeight;
                    }    //el.getContext().setCoordsize_()
                }
                return el;
            }
        };
        function onPropertyChange(e) {
            var el = e.srcElement;
            switch (e.propertyName) {
            case 'width':
                el.getContext().clearRect();
                el.style.width = el.attributes.width.nodeValue + 'px';
                // In IE8 this does not trigger onresize.
                el.firstChild.style.width = el.clientWidth + 'px';
                break;
            case 'height':
                el.getContext().clearRect();
                el.style.height = el.attributes.height.nodeValue + 'px';
                el.firstChild.style.height = el.clientHeight + 'px';
                break;
            }
        }
        function onResize(e) {
            var el = e.srcElement;
            if (el.firstChild) {
                el.firstChild.style.width = el.clientWidth + 'px';
                el.firstChild.style.height = el.clientHeight + 'px';
            }
        }
        G_vmlCanvasManager_.init();
        // precompute "00" to "FF"
        var decToHex = [];
        for (var i = 0; i < 16; i++) {
            for (var j = 0; j < 16; j++) {
                decToHex[i * 16 + j] = i.toString(16) + j.toString(16);
            }
        }
        function createMatrixIdentity() {
            return [
                [
                    1,
                    0,
                    0
                ],
                [
                    0,
                    1,
                    0
                ],
                [
                    0,
                    0,
                    1
                ]
            ];
        }
        function matrixMultiply(m1, m2) {
            var result = createMatrixIdentity();
            for (var x = 0; x < 3; x++) {
                for (var y = 0; y < 3; y++) {
                    var sum = 0;
                    for (var z = 0; z < 3; z++) {
                        sum += m1[x][z] * m2[z][y];
                    }
                    result[x][y] = sum;
                }
            }
            return result;
        }
        function getCoords(ctx, aX, aY) {
            var m = ctx.m_;
            return {
                x: Z * (aX * m[0][0] + aY * m[1][0] + m[2][0]) - Z2,
                y: Z * (aX * m[0][1] + aY * m[1][1] + m[2][1]) - Z2
            };
        }
        ;
        function getSkewedCoords(ctx, aX, aY) {
            var m = ctx.m_;
            return {
                x: Z * (aX * m[0][0] + aY * m[1][0]) - Z2,
                y: Z * (aX * m[0][1] + aY * m[1][1]) - Z2
            };
        }
        function copyState(o1, o2) {
            o2.fillStyle = o1.fillStyle;
            o2.lineCap = o1.lineCap;
            o2.lineJoin = o1.lineJoin;
            o2.lineWidth = o1.lineWidth;
            o2.miterLimit = o1.miterLimit;
            o2.shadowBlur = o1.shadowBlur;
            o2.shadowColor = o1.shadowColor;
            o2.shadowOffsetX = o1.shadowOffsetX;
            o2.shadowOffsetY = o1.shadowOffsetY;
            o2.strokeStyle = o1.strokeStyle;
            o2.globalAlpha = o1.globalAlpha;
            o2.font = o1.font;
            o2.textAlign = o1.textAlign;
            o2.textBaseline = o1.textBaseline;
            o2.scaleX_ = o1.scaleX_;
            o2.scaleY_ = o1.scaleY_;
            o2.x_ = o1.x_;
            o2.y_ = o1.y_;
            o2.lineScale_ = o1.lineScale_;
        }
        var colorData = {
            aliceblue: '#F0F8FF',
            antiquewhite: '#FAEBD7',
            aquamarine: '#7FFFD4',
            azure: '#F0FFFF',
            beige: '#F5F5DC',
            bisque: '#FFE4C4',
            black: '#000000',
            blanchedalmond: '#FFEBCD',
            blueviolet: '#8A2BE2',
            brown: '#A52A2A',
            burlywood: '#DEB887',
            cadetblue: '#5F9EA0',
            chartreuse: '#7FFF00',
            chocolate: '#D2691E',
            coral: '#FF7F50',
            cornflowerblue: '#6495ED',
            cornsilk: '#FFF8DC',
            crimson: '#DC143C',
            cyan: '#00FFFF',
            darkblue: '#00008B',
            darkcyan: '#008B8B',
            darkgoldenrod: '#B8860B',
            darkgray: '#A9A9A9',
            darkgreen: '#006400',
            darkgrey: '#A9A9A9',
            darkkhaki: '#BDB76B',
            darkmagenta: '#8B008B',
            darkolivegreen: '#556B2F',
            darkorange: '#FF8C00',
            darkorchid: '#9932CC',
            darkred: '#8B0000',
            darksalmon: '#E9967A',
            darkseagreen: '#8FBC8F',
            darkslateblue: '#483D8B',
            darkslategray: '#2F4F4F',
            darkslategrey: '#2F4F4F',
            darkturquoise: '#00CED1',
            darkviolet: '#9400D3',
            deeppink: '#FF1493',
            deepskyblue: '#00BFFF',
            dimgray: '#696969',
            dimgrey: '#696969',
            dodgerblue: '#1E90FF',
            firebrick: '#B22222',
            floralwhite: '#FFFAF0',
            forestgreen: '#228B22',
            gainsboro: '#DCDCDC',
            ghostwhite: '#F8F8FF',
            gold: '#FFD700',
            goldenrod: '#DAA520',
            grey: '#808080',
            greenyellow: '#ADFF2F',
            honeydew: '#F0FFF0',
            hotpink: '#FF69B4',
            indianred: '#CD5C5C',
            indigo: '#4B0082',
            ivory: '#FFFFF0',
            khaki: '#F0E68C',
            lavender: '#E6E6FA',
            lavenderblush: '#FFF0F5',
            lawngreen: '#7CFC00',
            lemonchiffon: '#FFFACD',
            lightblue: '#ADD8E6',
            lightcoral: '#F08080',
            lightcyan: '#E0FFFF',
            lightgoldenrodyellow: '#FAFAD2',
            lightgreen: '#90EE90',
            lightgrey: '#D3D3D3',
            lightpink: '#FFB6C1',
            lightsalmon: '#FFA07A',
            lightseagreen: '#20B2AA',
            lightskyblue: '#87CEFA',
            lightslategray: '#778899',
            lightslategrey: '#778899',
            lightsteelblue: '#B0C4DE',
            lightyellow: '#FFFFE0',
            limegreen: '#32CD32',
            linen: '#FAF0E6',
            magenta: '#FF00FF',
            mediumaquamarine: '#66CDAA',
            mediumblue: '#0000CD',
            mediumorchid: '#BA55D3',
            mediumpurple: '#9370DB',
            mediumseagreen: '#3CB371',
            mediumslateblue: '#7B68EE',
            mediumspringgreen: '#00FA9A',
            mediumturquoise: '#48D1CC',
            mediumvioletred: '#C71585',
            midnightblue: '#191970',
            mintcream: '#F5FFFA',
            mistyrose: '#FFE4E1',
            moccasin: '#FFE4B5',
            navajowhite: '#FFDEAD',
            oldlace: '#FDF5E6',
            olivedrab: '#6B8E23',
            orange: '#FFA500',
            orangered: '#FF4500',
            orchid: '#DA70D6',
            palegoldenrod: '#EEE8AA',
            palegreen: '#98FB98',
            paleturquoise: '#AFEEEE',
            palevioletred: '#DB7093',
            papayawhip: '#FFEFD5',
            peachpuff: '#FFDAB9',
            peru: '#CD853F',
            pink: '#FFC0CB',
            plum: '#DDA0DD',
            powderblue: '#B0E0E6',
            rosybrown: '#BC8F8F',
            royalblue: '#4169E1',
            saddlebrown: '#8B4513',
            salmon: '#FA8072',
            sandybrown: '#F4A460',
            seagreen: '#2E8B57',
            seashell: '#FFF5EE',
            sienna: '#A0522D',
            skyblue: '#87CEEB',
            slateblue: '#6A5ACD',
            slategray: '#708090',
            slategrey: '#708090',
            snow: '#FFFAFA',
            springgreen: '#00FF7F',
            steelblue: '#4682B4',
            tan: '#D2B48C',
            thistle: '#D8BFD8',
            tomato: '#FF6347',
            turquoise: '#40E0D0',
            violet: '#EE82EE',
            wheat: '#F5DEB3',
            whitesmoke: '#F5F5F5',
            yellowgreen: '#9ACD32'
        };
        function getRgbHslContent(styleString) {
            var start = styleString.indexOf('(', 3);
            var end = styleString.indexOf(')', start + 1);
            var parts = styleString.substring(start + 1, end).split(',');
            // add alpha if needed
            if (parts.length != 4 || styleString.charAt(3) != 'a') {
                parts[3] = 1;
            }
            return parts;
        }
        function percent(s) {
            return parseFloat(s) / 100;
        }
        function clamp(v, min, max) {
            return Math.min(max, Math.max(min, v));
        }
        function hslToRgb(parts) {
            var r, g, b, h, s, l;
            h = parseFloat(parts[0]) / 360 % 360;
            if (h < 0)
                h++;
            s = clamp(percent(parts[1]), 0, 1);
            l = clamp(percent(parts[2]), 0, 1);
            if (s == 0) {
                r = g = b = l;    // achromatic
            } else {
                var q = l < 0.5 ? l * (1 + s) : l + s - l * s;
                var p = 2 * l - q;
                r = hueToRgb(p, q, h + 1 / 3);
                g = hueToRgb(p, q, h);
                b = hueToRgb(p, q, h - 1 / 3);
            }
            return '#' + decToHex[Math.floor(r * 255)] + decToHex[Math.floor(g * 255)] + decToHex[Math.floor(b * 255)];
        }
        function hueToRgb(m1, m2, h) {
            if (h < 0)
                h++;
            if (h > 1)
                h--;
            if (6 * h < 1)
                return m1 + (m2 - m1) * 6 * h;
            else if (2 * h < 1)
                return m2;
            else if (3 * h < 2)
                return m1 + (m2 - m1) * (2 / 3 - h) * 6;
            else
                return m1;
        }
        var processStyleCache = {};
        function processStyle(styleString) {
            if (styleString in processStyleCache) {
                return processStyleCache[styleString];
            }
            var str, alpha = 1;
            styleString = String(styleString);
            if (styleString.charAt(0) == '#') {
                str = styleString;
            } else if (/^rgb/.test(styleString)) {
                var parts = getRgbHslContent(styleString);
                var str = '#', n;
                for (var i = 0; i < 3; i++) {
                    if (parts[i].indexOf('%') != -1) {
                        n = Math.floor(percent(parts[i]) * 255);
                    } else {
                        n = +parts[i];
                    }
                    str += decToHex[clamp(n, 0, 255)];
                }
                alpha = +parts[3];
            } else if (/^hsl/.test(styleString)) {
                var parts = getRgbHslContent(styleString);
                str = hslToRgb(parts);
                alpha = parts[3];
            } else {
                str = colorData[styleString] || styleString;
            }
            return processStyleCache[styleString] = {
                color: str,
                alpha: alpha
            };
        }
        var DEFAULT_STYLE = {
            style: 'normal',
            variant: 'normal',
            weight: 'normal',
            size: 12,
            //10
            family: '微软雅黑'    //'sans-serif'
        };
        // Internal text style cache
        var fontStyleCache = {};
        function processFontStyle(styleString) {
            if (fontStyleCache[styleString]) {
                return fontStyleCache[styleString];
            }
            var el = document.createElement('div');
            var style = el.style;
            var fontFamily;
            try {
                style.font = styleString;
                fontFamily = style.fontFamily.split(',')[0];
            } catch (ex) {
            }
            return fontStyleCache[styleString] = {
                style: style.fontStyle || DEFAULT_STYLE.style,
                variant: style.fontVariant || DEFAULT_STYLE.variant,
                weight: style.fontWeight || DEFAULT_STYLE.weight,
                size: style.fontSize || DEFAULT_STYLE.size,
                family: fontFamily || DEFAULT_STYLE.family
            };
        }
        function getComputedStyle(style, element) {
            var computedStyle = {};
            for (var p in style) {
                computedStyle[p] = style[p];
            }
            // Compute the size
            var canvasFontSize = parseFloat(element.currentStyle.fontSize), fontSize = parseFloat(style.size);
            if (typeof style.size == 'number') {
                computedStyle.size = style.size;
            } else if (style.size.indexOf('px') != -1) {
                computedStyle.size = fontSize;
            } else if (style.size.indexOf('em') != -1) {
                computedStyle.size = canvasFontSize * fontSize;
            } else if (style.size.indexOf('%') != -1) {
                computedStyle.size = canvasFontSize / 100 * fontSize;
            } else if (style.size.indexOf('pt') != -1) {
                computedStyle.size = fontSize / 0.75;
            } else {
                computedStyle.size = canvasFontSize;
            }
            // Different scaling between normal text and VML text. This was found using
            // trial and error to get the same size as non VML text.
            //computedStyle.size *= 0.981;
            return computedStyle;
        }
        function buildStyle(style) {
            return style.style + ' ' + style.variant + ' ' + style.weight + ' ' + style.size + 'px \'' + style.family + '\'';
        }
        var lineCapMap = {
            'butt': 'flat',
            'round': 'round'
        };
        function processLineCap(lineCap) {
            return lineCapMap[lineCap] || 'square';
        }
        /**
   * This class implements CanvasRenderingContext2D interface as described by
   * the WHATWG.
   * @param {HTMLElement} canvasElement The element that the 2D context should
   * be associated with
   */
        function CanvasRenderingContext2D_(canvasElement) {
            this.m_ = createMatrixIdentity();
            this.mStack_ = [];
            this.aStack_ = [];
            this.currentPath_ = [];
            // Canvas context properties
            this.strokeStyle = '#000';
            this.fillStyle = '#000';
            this.lineWidth = 1;
            this.lineJoin = 'miter';
            this.lineCap = 'butt';
            this.miterLimit = Z * 1;
            this.globalAlpha = 1;
            // this.font = '10px sans-serif';
            this.font = '12px 微软雅黑';
            // 决定还是改这吧，影响代价最小
            this.textAlign = 'left';
            this.textBaseline = 'alphabetic';
            this.canvas = canvasElement;
            var cssText = 'width:' + canvasElement.clientWidth + 'px;height:' + canvasElement.clientHeight + 'px;overflow:hidden;position:absolute';
            var el = canvasElement.ownerDocument.createElement('div');
            el.style.cssText = cssText;
            canvasElement.appendChild(el);
            var overlayEl = el.cloneNode(false);
            // Use a non transparent background.
            overlayEl.style.backgroundColor = '#fff';
            //red, I don't know why, it work! 
            overlayEl.style.filter = 'alpha(opacity=0)';
            canvasElement.appendChild(overlayEl);
            this.element_ = el;
            this.scaleX_ = 1;
            this.scaleY_ = 1;
            this.x_ = 0;
            this.y_ = 0;
            this.lineScale_ = 1;
            this.html_ = '';
        }
        var contextPrototype = CanvasRenderingContext2D_.prototype;
        contextPrototype.clearRect = function () {
            if (this.textMeasureEl_) {
                this.textMeasureEl_.removeNode(true);
                this.textMeasureEl_ = null;
            }
            this.element_.innerHTML = '';
        };
        contextPrototype.flush = function () {
            this.element_.insertAdjacentHTML('beforeEnd', this.html_);
            this.html_ = '';
        };
        contextPrototype.beginPath = function () {
            // TODO: Branch current matrix so that save/restore has no effect
            //       as per safari docs.
            this.currentPath_ = [];
        };
        contextPrototype.moveTo = function (aX, aY) {
            var p = getSkewedCoords(this, aX, aY);
            p.type = 'moveTo';
            this.currentPath_.push(p);
            this.currentX_ = p.x;
            this.currentY_ = p.y;
        };
        contextPrototype.lineTo = function (aX, aY) {
            var p = getSkewedCoords(this, aX, aY);
            p.type = 'lineTo';
            this.currentPath_.push(p);
            this.currentX_ = p.x;
            this.currentY_ = p.y;
        };
        contextPrototype.bezierCurveTo = function (aCP1x, aCP1y, aCP2x, aCP2y, aX, aY) {
            var p = getSkewedCoords(this, aX, aY);
            var cp1 = getSkewedCoords(this, aCP1x, aCP1y);
            var cp2 = getSkewedCoords(this, aCP2x, aCP2y);
            bezierCurveTo(this, cp1, cp2, p);
        };
        // Helper function that takes the already fixed cordinates.
        function bezierCurveTo(self, cp1, cp2, p) {
            self.currentPath_.push({
                type: 'bezierCurveTo',
                cp1x: cp1.x,
                cp1y: cp1.y,
                cp2x: cp2.x,
                cp2y: cp2.y,
                x: p.x,
                y: p.y
            });
            self.currentX_ = p.x;
            self.currentY_ = p.y;
        }
        contextPrototype.quadraticCurveTo = function (aCPx, aCPy, aX, aY) {
            // the following is lifted almost directly from
            // http://developer.mozilla.org/en/docs/Canvas_tutorial:Drawing_shapes
            var cp = getSkewedCoords(this, aCPx, aCPy);
            var p = getSkewedCoords(this, aX, aY);
            var cp1 = {
                x: this.currentX_ + 2 / 3 * (cp.x - this.currentX_),
                y: this.currentY_ + 2 / 3 * (cp.y - this.currentY_)
            };
            var cp2 = {
                x: cp1.x + (p.x - this.currentX_) / 3,
                y: cp1.y + (p.y - this.currentY_) / 3
            };
            bezierCurveTo(this, cp1, cp2, p);
        };
        contextPrototype.arc = function (aX, aY, aRadius, aStartAngle, aEndAngle, aClockwise) {
            aRadius *= Z;
            var arcType = aClockwise ? 'at' : 'wa';
            var xStart = aX + mc(aStartAngle) * aRadius - Z2;
            var yStart = aY + ms(aStartAngle) * aRadius - Z2;
            var xEnd = aX + mc(aEndAngle) * aRadius - Z2;
            var yEnd = aY + ms(aEndAngle) * aRadius - Z2;
            // IE won't render arches drawn counter clockwise if xStart == xEnd.
            if (xStart == xEnd && !aClockwise) {
                xStart += 0.125;    // Offset xStart by 1/80 of a pixel. Use something
                                    // that can be represented in binary
            }
            var p = getSkewedCoords(this, aX, aY);
            var pStart = getSkewedCoords(this, xStart, yStart);
            var pEnd = getSkewedCoords(this, xEnd, yEnd);
            this.currentPath_.push({
                type: arcType,
                x: p.x,
                y: p.y,
                radius: aRadius,
                xStart: pStart.x,
                yStart: pStart.y,
                xEnd: pEnd.x,
                yEnd: pEnd.y
            });
        };
        contextPrototype.rect = function (aX, aY, aWidth, aHeight) {
            this.moveTo(aX, aY);
            this.lineTo(aX + aWidth, aY);
            this.lineTo(aX + aWidth, aY + aHeight);
            this.lineTo(aX, aY + aHeight);
            this.closePath();
        };
        contextPrototype.strokeRect = function (aX, aY, aWidth, aHeight) {
            var oldPath = this.currentPath_;
            this.beginPath();
            this.moveTo(aX, aY);
            this.lineTo(aX + aWidth, aY);
            this.lineTo(aX + aWidth, aY + aHeight);
            this.lineTo(aX, aY + aHeight);
            this.closePath();
            this.stroke();
            this.currentPath_ = oldPath;
        };
        contextPrototype.fillRect = function (aX, aY, aWidth, aHeight) {
            var oldPath = this.currentPath_;
            this.beginPath();
            this.moveTo(aX, aY);
            this.lineTo(aX + aWidth, aY);
            this.lineTo(aX + aWidth, aY + aHeight);
            this.lineTo(aX, aY + aHeight);
            this.closePath();
            this.fill();
            this.currentPath_ = oldPath;
        };
        contextPrototype.createLinearGradient = function (aX0, aY0, aX1, aY1) {
            var gradient = new CanvasGradient_('gradient');
            gradient.x0_ = aX0;
            gradient.y0_ = aY0;
            gradient.x1_ = aX1;
            gradient.y1_ = aY1;
            return gradient;
        };
        contextPrototype.createRadialGradient = function (aX0, aY0, aR0, aX1, aY1, aR1) {
            var gradient = new CanvasGradient_('gradientradial');
            gradient.x0_ = aX0;
            gradient.y0_ = aY0;
            gradient.r0_ = aR0;
            gradient.x1_ = aX1;
            gradient.y1_ = aY1;
            gradient.r1_ = aR1;
            return gradient;
        };
        contextPrototype.drawImage = function (image, var_args) {
            var dx, dy, dw, dh, sx, sy, sw, sh;
            // to find the original width we overide the width and height
            var oldRuntimeWidth = image.runtimeStyle.width;
            var oldRuntimeHeight = image.runtimeStyle.height;
            image.runtimeStyle.width = 'auto';
            image.runtimeStyle.height = 'auto';
            // get the original size
            var w = image.width;
            var h = image.height;
            var m_ = this.m_;
            // and remove overides
            image.runtimeStyle.width = oldRuntimeWidth;
            image.runtimeStyle.height = oldRuntimeHeight;
            if (arguments.length == 3) {
                dx = arguments[1];
                dy = arguments[2];
                sx = sy = 0;
                sw = dw = w;
                sh = dh = h;
            } else if (arguments.length == 5) {
                dx = arguments[1];
                dy = arguments[2];
                dw = arguments[3];
                dh = arguments[4];
                sx = sy = 0;
                sw = w;
                sh = h;
            } else if (arguments.length == 9) {
                sx = arguments[1];
                sy = arguments[2];
                sw = arguments[3];
                sh = arguments[4];
                dx = arguments[5];
                dy = arguments[6];
                dw = arguments[7];
                dh = arguments[8];
            } else {
                throw Error('Invalid number of arguments');
            }
            var w2 = sw / 2;
            var h2 = sh / 2;
            var vmlStr = [];
            var W = 10;
            var H = 10;
            var skewed = m_[1] || m_[2];
            var cropped = sx || sy;
            var scaleX = this.scaleX_;
            var scaleY = this.scaleY_;
            var x = this.x_ + dx * scaleX;
            var y = this.y_ + dy * scaleY;
            // If filters are necessary (rotation exists), create them
            // filters are bog-slow, so only create them if abbsolutely necessary
            // The following check doesn't account for skews (which don't exist
            // in the canvas spec (yet) anyway.
            if (!skewed || !cropped) {
                vmlStr.push('<img src="', image.src, '"', 'style="position:absolute;left:', x, 'px;top:', y, 'px;');
                vmlStr.push('width:', scaleX * dw / sw * w, 'px;height:', scaleY * dh / sh * h, 'px;');
                if (this.globalAlpha < 1) {
                    vmlStr.push('filter:alpha(opacity=', mr(this.globalAlpha * 100) + ')');
                }
                vmlStr.push('" />');
            } else if (skewed) {
                // For some reason that I've now forgotten, using divs didn't work
                vmlStr.push(' <g_vml_:group', ' coordsize="', Z * W, ',', Z * H, '"', ' coordorigin="0,0"', ' style="width:', W, 'px;height:', H, 'px;position:absolute;');
                var d = getCoords(this, dx, dy);
                var filter = [];
                // Note the 12/21 reversal
                filter.push('M11=', this.m_[0][0] / scaleX, ',', 'M12=', this.m_[1][0] / scaleY, ',', 'M21=', this.m_[0][1] / scaleX, ',', 'M22=', this.m_[1][1] / scaleY, ',', 'Dx=', mr(d.x / Z), ',', 'Dy=', mr(d.y / Z), '');
                // Bounding box calculation (need to minimize displayed area so that
                // filters don't waste time on unused pixels.
                var max = d;
                var c2 = getCoords(this, dx + dw, dy);
                var c3 = getCoords(this, dx, dy + dh);
                var c4 = getCoords(this, dx + dw, dy + dh);
                max.x = m.max(max.x, c2.x, c3.x, c4.x);
                max.y = m.max(max.y, c2.y, c3.y, c4.y);
                vmlStr.push('padding:0 ', mr(max.x / Z), 'px ', mr(max.y / Z), 'px 0;filter:progid:DXImageTransform.Microsoft.Matrix(', filter.join(''), ', SizingMethod=\'clip\');>');
                if (cropped) {
                    vmlStr.push('<div style="overflow: hidden; width:', Math.ceil((dw + sx * dw / sw) * scaleX), 'px;', ' height:', Math.ceil((dh + sy * dh / sh) * scaleY), 'px;', ' filter:progid:DxImageTransform.Microsoft.Matrix(Dx=', -sx * dw / sw * scaleX, ',Dy=', -sy * dh / sh * scaleY, ');">');
                }
                vmlStr.push('<img src="', image.src, '"', 'style="position:absolute;');
                vmlStr.push('width:', scaleX * dw / sw * w, 'px;height:', scaleY * dh / sh * h, 'px;');
                if (this.globalAlpha < 1) {
                    vmlStr.push('filter:alpha(opacity=', mr(this.globalAlpha * 100) + ')');
                }
                vmlStr.push('" />');
                if (cropped) {
                    vmlStr.push('</div>');
                }
                vmlStr.push('</g_vml_:group>');
            } else {
                // Apply scales to width and height
                vmlStr.push('<div style="overflow: hidden; width:', Math.ceil((dw + sx * dw / sw) * scaleX), 'px;', ' height:', Math.ceil((dh + sy * dh / sh) * scaleY), 'px;', 'position:absolute;left:', x, 'px;', 'top:', y, 'px;', ' filter:progid:DxImageTransform.Microsoft.Matrix(Dx=', -sx * dw / sw * scaleX, ',Dy=', -sy * dh / sh * scaleY, ');">');
                vmlStr.push('<img src="', image.src, '"', 'style="position:absolute;');
                vmlStr.push('width:', scaleX * dw / sw * w, 'px;height:', scaleY * dh / sh * h, 'px;');
                if (this.globalAlpha < 1) {
                    vmlStr.push('filter:alpha(opacity=', mr(this.globalAlpha * 100) + ')');
                }
                vmlStr.push('" /></div>');
            }
            this.html_ += vmlStr.join('');
        };
        contextPrototype.stroke = function (aFill) {
            var lineStr = [];
            var lineOpen = false;
            var W = 10;
            var H = 10;
            var x_ = this.x_;
            var y_ = this.y_;
            lineStr.push('<g_vml_:shape', ' filled="', !!aFill, '"', ' style="position:absolute;width:', W, 'px;height:', H, 'px;', 'left:', x_, 'px;top:', y_, 'px;"', ' coordorigin="0,0"', ' coordsize="', Z * W, ',', Z * H, '"', ' stroked="', !aFill, '"', ' path="');
            var newSeq = false;
            var min = {
                x: null,
                y: null
            };
            var max = {
                x: null,
                y: null
            };
            for (var i = 0; i < this.currentPath_.length; i++) {
                var p = this.currentPath_[i];
                var c;
                switch (p.type) {
                case 'moveTo':
                    c = p;
                    lineStr.push(' m ', mr(p.x), ',', mr(p.y));
                    break;
                case 'lineTo':
                    lineStr.push(' l ', mr(p.x), ',', mr(p.y));
                    break;
                case 'close':
                    lineStr.push(' x ');
                    p = null;
                    break;
                case 'bezierCurveTo':
                    lineStr.push(' c ', mr(p.cp1x), ',', mr(p.cp1y), ',', mr(p.cp2x), ',', mr(p.cp2y), ',', mr(p.x), ',', mr(p.y));
                    break;
                case 'at':
                case 'wa':
                    lineStr.push(' ', p.type, ' ', mr(p.x - this.scaleX_ * p.radius), ',', mr(p.y - this.scaleY_ * p.radius), ' ', mr(p.x + this.scaleX_ * p.radius), ',', mr(p.y + this.scaleY_ * p.radius), ' ', mr(p.xStart), ',', mr(p.yStart), ' ', mr(p.xEnd), ',', mr(p.yEnd));
                    break;
                }
                // TODO: Following is broken for curves due to
                //       move to proper paths.
                // Figure out dimensions so we can do gradient fills
                // properly
                if (p) {
                    if (min.x == null || p.x < min.x) {
                        min.x = p.x;
                    }
                    if (max.x == null || p.x > max.x) {
                        max.x = p.x;
                    }
                    if (min.y == null || p.y < min.y) {
                        min.y = p.y;
                    }
                    if (max.y == null || p.y > max.y) {
                        max.y = p.y;
                    }
                }
            }
            lineStr.push(' ">');
            if (!aFill) {
                appendStroke(this, lineStr);
            } else {
                appendFill(this, lineStr, min, max);
            }
            lineStr.push('</g_vml_:shape>');
            this.html_ += lineStr.join('');
        };
        function appendStroke(ctx, lineStr) {
            var a = processStyle(ctx.strokeStyle);
            var color = a.color;
            var opacity = a.alpha * ctx.globalAlpha;
            var lineWidth = ctx.lineScale_ * ctx.lineWidth;
            // VML cannot correctly render a line if the width is less than 1px.
            // In that case, we dilute the color to make the line look thinner.
            if (lineWidth < 1) {
                opacity *= lineWidth;
            }
            lineStr.push('<g_vml_:stroke', ' opacity="', opacity, '"', ' joinstyle="', ctx.lineJoin, '"', ' miterlimit="', ctx.miterLimit, '"', ' endcap="', processLineCap(ctx.lineCap), '"', ' weight="', lineWidth, 'px"', ' color="', color, '" />');
        }
        function appendFill(ctx, lineStr, min, max) {
            var fillStyle = ctx.fillStyle;
            var arcScaleX = ctx.scaleX_;
            var arcScaleY = ctx.scaleY_;
            var width = max.x - min.x;
            var height = max.y - min.y;
            if (fillStyle instanceof CanvasGradient_) {
                // TODO: Gradients transformed with the transformation matrix.
                var angle = 0;
                var focus = {
                    x: 0,
                    y: 0
                };
                // additional offset
                var shift = 0;
                // scale factor for offset
                var expansion = 1;
                if (fillStyle.type_ == 'gradient') {
                    var x0 = fillStyle.x0_ / arcScaleX;
                    var y0 = fillStyle.y0_ / arcScaleY;
                    var x1 = fillStyle.x1_ / arcScaleX;
                    var y1 = fillStyle.y1_ / arcScaleY;
                    var p0 = getCoords(ctx, x0, y0);
                    var p1 = getCoords(ctx, x1, y1);
                    var dx = p1.x - p0.x;
                    var dy = p1.y - p0.y;
                    angle = Math.atan2(dx, dy) * 180 / Math.PI;
                    // The angle should be a non-negative number.
                    if (angle < 0) {
                        angle += 360;
                    }
                    // Very small angles produce an unexpected result because they are
                    // converted to a scientific notation string.
                    if (angle < 0.000001) {
                        angle = 0;
                    }
                } else {
                    var p0 = getCoords(ctx, fillStyle.x0_, fillStyle.y0_);
                    focus = {
                        x: (p0.x - min.x) / width,
                        y: (p0.y - min.y) / height
                    };
                    width /= arcScaleX * Z;
                    height /= arcScaleY * Z;
                    var dimension = m.max(width, height);
                    shift = 2 * fillStyle.r0_ / dimension;
                    expansion = 2 * fillStyle.r1_ / dimension - shift;
                }
                // We need to sort the color stops in ascending order by offset,
                // otherwise IE won't interpret it correctly.
                var stops = fillStyle.colors_;
                stops.sort(function (cs1, cs2) {
                    return cs1.offset - cs2.offset;
                });
                var length = stops.length;
                var color1 = stops[0].color;
                var color2 = stops[length - 1].color;
                var opacity1 = stops[0].alpha * ctx.globalAlpha;
                var opacity2 = stops[length - 1].alpha * ctx.globalAlpha;
                var colors = [];
                for (var i = 0; i < length; i++) {
                    var stop = stops[i];
                    colors.push(stop.offset * expansion + shift + ' ' + stop.color);
                }
                // When colors attribute is used, the meanings of opacity and o:opacity2
                // are reversed.
                lineStr.push('<g_vml_:fill type="', fillStyle.type_, '"', ' method="none" focus="100%"', ' color="', color1, '"', ' color2="', color2, '"', ' colors="', colors.join(','), '"', ' opacity="', opacity2, '"', ' g_o_:opacity2="', opacity1, '"', ' angle="', angle, '"', ' focusposition="', focus.x, ',', focus.y, '" />');
            } else if (fillStyle instanceof CanvasPattern_) {
                if (width && height) {
                    var deltaLeft = -min.x;
                    var deltaTop = -min.y;
                    lineStr.push('<g_vml_:fill', ' position="', deltaLeft / width * arcScaleX * arcScaleX, ',', deltaTop / height * arcScaleY * arcScaleY, '"', ' type="tile"', // TODO: Figure out the correct size to fit the scale.
                    //' size="', w, 'px ', h, 'px"',
                    ' src="', fillStyle.src_, '" />');
                }
            } else {
                var a = processStyle(ctx.fillStyle);
                var color = a.color;
                var opacity = a.alpha * ctx.globalAlpha;
                lineStr.push('<g_vml_:fill color="', color, '" opacity="', opacity, '" />');
            }
        }
        contextPrototype.fill = function () {
            this.stroke(true);
        };
        contextPrototype.closePath = function () {
            this.currentPath_.push({ type: 'close' });
        };
        contextPrototype.save = function () {
            var o = {};
            copyState(this, o);
            this.aStack_.push(o);
            this.mStack_.push(this.m_);
            this.m_ = matrixMultiply(createMatrixIdentity(), this.m_);
        };
        contextPrototype.restore = function () {
            if (this.aStack_.length) {
                copyState(this.aStack_.pop(), this);
                this.m_ = this.mStack_.pop();
            }
        };
        function matrixIsFinite(m) {
            return isFinite(m[0][0]) && isFinite(m[0][1]) && isFinite(m[1][0]) && isFinite(m[1][1]) && isFinite(m[2][0]) && isFinite(m[2][1]);
        }
        function setM(ctx, m, updateLineScale) {
            if (!matrixIsFinite(m)) {
                return;
            }
            ctx.m_ = m;
            ctx.scaleX_ = Math.sqrt(m[0][0] * m[0][0] + m[0][1] * m[0][1]);
            ctx.scaleY_ = Math.sqrt(m[1][0] * m[1][0] + m[1][1] * m[1][1]);
            ctx.x_ = m[2][0];
            ctx.y_ = m[2][1];
            if (updateLineScale) {
                // Get the line scale.
                // Determinant of this.m_ means how much the area is enlarged by the
                // transformation. So its square root can be used as a scale factor
                // for width.
                var det = m[0][0] * m[1][1] - m[0][1] * m[1][0];
                ctx.lineScale_ = sqrt(abs(det));
            }
        }
        contextPrototype.translate = function (aX, aY) {
            var m1 = [
                [
                    1,
                    0,
                    0
                ],
                [
                    0,
                    1,
                    0
                ],
                [
                    aX,
                    aY,
                    1
                ]
            ];
            setM(this, matrixMultiply(m1, this.m_), false);
        };
        contextPrototype.rotate = function (aRot) {
            var c = mc(aRot);
            var s = ms(aRot);
            var m1 = [
                [
                    c,
                    s,
                    0
                ],
                [
                    -s,
                    c,
                    0
                ],
                [
                    0,
                    0,
                    1
                ]
            ];
            setM(this, matrixMultiply(m1, this.m_), false);
        };
        contextPrototype.scale = function (aX, aY) {
            var m1 = [
                [
                    aX,
                    0,
                    0
                ],
                [
                    0,
                    aY,
                    0
                ],
                [
                    0,
                    0,
                    1
                ]
            ];
            setM(this, matrixMultiply(m1, this.m_), true);
        };
        contextPrototype.transform = function (m11, m12, m21, m22, dx, dy) {
            var m1 = [
                [
                    m11,
                    m12,
                    0
                ],
                [
                    m21,
                    m22,
                    0
                ],
                [
                    dx,
                    dy,
                    1
                ]
            ];
            setM(this, matrixMultiply(m1, this.m_), true);
        };
        contextPrototype.setTransform = function (m11, m12, m21, m22, dx, dy) {
            var m = [
                [
                    m11,
                    m12,
                    0
                ],
                [
                    m21,
                    m22,
                    0
                ],
                [
                    dx,
                    dy,
                    1
                ]
            ];
            setM(this, m, true);
        };
        /**
   * The text drawing function.
   * The maxWidth argument isn't taken in account, since no browser supports
   * it yet.
   */
        contextPrototype.drawText_ = function (text, x, y, maxWidth, stroke) {
            var m = this.m_, delta = 1000, left = 0, right = delta, offset = {
                    x: 0,
                    y: 0
                }, lineStr = [];
            var fontStyle = getComputedStyle(processFontStyle(this.font), this.element_);
            var fontStyleString = buildStyle(fontStyle);
            var elementStyle = this.element_.currentStyle;
            var textAlign = this.textAlign.toLowerCase();
            switch (textAlign) {
            case 'left':
            case 'center':
            case 'right':
                break;
            case 'end':
                textAlign = elementStyle.direction == 'ltr' ? 'right' : 'left';
                break;
            case 'start':
                textAlign = elementStyle.direction == 'rtl' ? 'right' : 'left';
                break;
            default:
                textAlign = 'left';
            }
            // 1.75 is an arbitrary number, as there is no info about the text baseline
            switch (this.textBaseline) {
            case 'hanging':
            case 'top':
                offset.y = fontStyle.size / 1.75;
                break;
            case 'middle':
                break;
            default:
            case null:
            case 'alphabetic':
            case 'ideographic':
            case 'bottom':
                offset.y = -fontStyle.size / 2.25;
                break;
            }
            switch (textAlign) {
            case 'right':
                left = delta;
                right = 0.05;
                break;
            case 'center':
                left = right = delta / 2;
                break;
            }
            var d = getCoords(this, x + offset.x, y + offset.y);
            lineStr.push('<g_vml_:line from="', -left, ' 0" to="', right, ' 0.05" ', ' coordsize="100 100" coordorigin="0 0"', ' filled="', !stroke, '" stroked="', !!stroke, '" style="position:absolute;width:1px;height:1px;">');
            if (stroke) {
                appendStroke(this, lineStr);
            } else {
                // TODO: Fix the min and max params.
                appendFill(this, lineStr, {
                    x: -left,
                    y: 0
                }, {
                    x: right,
                    y: fontStyle.size
                });
            }
            var skewM = m[0][0].toFixed(3) + ',' + m[1][0].toFixed(3) + ',' + m[0][1].toFixed(3) + ',' + m[1][1].toFixed(3) + ',0,0';
            var skewOffset = mr(d.x / Z) + ',' + mr(d.y / Z);
            lineStr.push('<g_vml_:skew on="t" matrix="', skewM, '" ', ' offset="', skewOffset, '" origin="', left, ' 0" />', '<g_vml_:path textpathok="true" />', '<g_vml_:textpath on="true" string="', encodeHtmlAttribute(text), '" style="v-text-align:', textAlign, ';font:', encodeHtmlAttribute(fontStyleString), '" /></g_vml_:line>');
            this.html_ += lineStr.join('');
        };
        contextPrototype.fillText = function (text, x, y, maxWidth) {
            this.drawText_(text, x, y, maxWidth, false);
        };
        contextPrototype.strokeText = function (text, x, y, maxWidth) {
            this.drawText_(text, x, y, maxWidth, true);
        };
        contextPrototype.measureText = function (text) {
            if (!this.textMeasureEl_) {
                var s = '<span style="position:absolute;' + 'top:-20000px;left:0;padding:0;margin:0;border:none;' + 'white-space:pre;"></span>';
                this.element_.insertAdjacentHTML('beforeEnd', s);
                this.textMeasureEl_ = this.element_.lastChild;
            }
            var doc = this.element_.ownerDocument;
            this.textMeasureEl_.innerHTML = '';
            this.textMeasureEl_.style.font = this.font;
            // Don't use innerHTML or innerText because they allow markup/whitespace.
            this.textMeasureEl_.appendChild(doc.createTextNode(text));
            return { width: this.textMeasureEl_.offsetWidth };
        };
        /******** STUBS ********/
        contextPrototype.clip = function () {
        };
        contextPrototype.arcTo = function () {
        };
        contextPrototype.createPattern = function (image, repetition) {
            return new CanvasPattern_(image, repetition);
        };
        // Gradient / Pattern Stubs
        function CanvasGradient_(aType) {
            this.type_ = aType;
            this.x0_ = 0;
            this.y0_ = 0;
            this.r0_ = 0;
            this.x1_ = 0;
            this.y1_ = 0;
            this.r1_ = 0;
            this.colors_ = [];
        }
        CanvasGradient_.prototype.addColorStop = function (aOffset, aColor) {
            aColor = processStyle(aColor);
            this.colors_.push({
                offset: aOffset,
                color: aColor.color,
                alpha: aColor.alpha
            });
        };
        function CanvasPattern_(image, repetition) {
            assertImageIsValid(image);
            switch (repetition) {
            case 'repeat':
            case null:
            case '':
                this.repetition_ = 'repeat';
                break;
            case 'repeat-x':
            case 'repeat-y':
            case 'no-repeat':
                this.repetition_ = repetition;
                break;
            default:
                throwException('SYNTAX_ERR');
            }
            this.src_ = image.src;
            this.width_ = image.width;
            this.height_ = image.height;
        }
        function throwException(s) {
            throw new DOMException_(s);
        }
        function assertImageIsValid(img) {
            if (!img || img.nodeType != 1 || img.tagName != 'IMG') {
                throwException('TYPE_MISMATCH_ERR');
            }
            if (img.readyState != 'complete') {
                throwException('INVALID_STATE_ERR');
            }
        }
        function DOMException_(s) {
            this.code = this[s];
            this.message = s + ': DOM Exception ' + this.code;
        }
        var p = DOMException_.prototype = new Error();
        p.INDEX_SIZE_ERR = 1;
        p.DOMSTRING_SIZE_ERR = 2;
        p.HIERARCHY_REQUEST_ERR = 3;
        p.WRONG_DOCUMENT_ERR = 4;
        p.INVALID_CHARACTER_ERR = 5;
        p.NO_DATA_ALLOWED_ERR = 6;
        p.NO_MODIFICATION_ALLOWED_ERR = 7;
        p.NOT_FOUND_ERR = 8;
        p.NOT_SUPPORTED_ERR = 9;
        p.INUSE_ATTRIBUTE_ERR = 10;
        p.INVALID_STATE_ERR = 11;
        p.SYNTAX_ERR = 12;
        p.INVALID_MODIFICATION_ERR = 13;
        p.NAMESPACE_ERR = 14;
        p.INVALID_ACCESS_ERR = 15;
        p.VALIDATION_ERR = 16;
        p.TYPE_MISMATCH_ERR = 17;
        // set up externs
        G_vmlCanvasManager = G_vmlCanvasManager_;
        CanvasRenderingContext2D = CanvasRenderingContext2D_;
        CanvasGradient = CanvasGradient_;
        CanvasPattern = CanvasPattern_;
        DOMException = DOMException_;
    }());
}    // if
else {
    // make the canvas test simple by kener.linfeng@gmail.com
    G_vmlCanvasManager = false;
}
module.exports = G_vmlCanvasManager || module.exports;;    // define
